Automatically deflected gun sight



NO V. 21, 1933. Rgc, COUPLAND 1,935,615

AUTMATICALLY DEFLECTED GUN SIGl-KIT Filed .April 2, 1929 3 Sheets-Sheet1 d fawn:

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'Rthard [flulgnland Nov. 21, 1933. R c, couPLAND AUTOMATIGALLYDEFLEFGTED GUN SIGHT Filed'April 2, 1929 s sheets4sheet 2 gru/ventenRichard E- England MM @M atten m q Nov. 21, 1933. R Q CUPLAND 1,935,615

AUTQMATICALLY DEFLECTED GUN SIGH'T Filed April 2, 1929 3 Sheets-sheet :s

Richard E- Etprland vPatented Nov. 2l,

wagersI appiicaaonlamu 2, 1929. serial No. 351,5897

einser the aus @e n s, ists, as @naar apar so, 192s; si@ o. o. 757) Theinvention described herein may be manufactured and used by or for theGoverment for governmental purposes, without the paymentsto me of anyroyalty thereon. i

5 This invention relates to variable speed mechanism and is particularlydesigned for hre control apparatus\ employed under conditions whereeither or both the gun or bomb platform and target are moving at highspeeds.

Where a gun and target are relatively movable,

the directing of the gun must take into consideration a horizontal andvertical lead which are determined by the relative angular travel asinuenced by the velocity and trajectory' of the projectile, converselythis will be true for a sighting device in bombing' from aircraft exceptfor the vertical control.

i The object of this invention is the provision of a nre controlapparatus in which members interpreting the rate of the relative angulartravel in both the horizontal and vertical -planes are associated with aconstant speed device to prof duce a variable speed mechanism displacingthe line of sight of the aiming device to correct for the futureposition of the target or otherwise to indicate the lead.

With the foregoing and other objects in view, the invention resides inthe novel arrangement `and combination of parts and in the details of,construction hereinafter described and claimed, it being understoodthat changes in the precise embodiment of the invention herein disclosedmay be made within the scope of what is claimed twithout departing fromthe spirit of the invenion.

\ A practical embodiment of the invention is illustrated in theaccompanying drawings, where- Fig. 1 is a view in side elevation of theimproved mechanism as applied to the sighting system of a' gun;

Fig. 2 is a plan view thereof; Fig. 3 is a sectional viewtaken on theline 3-3 of Fig. 1; 4

Fig.4'is an enlarged longitudinal sectional view through the ratemechanism;

Fig. 5 is aplan view of Fig. 4; Fig..6 is an enlarged detail view o! thepawl; and Figs. I and are detail views of diierent forms of sights.

Broadly, the invention consists in the provision of a series of slidesmovable at a predetermined rate of speed and means for moving the slidessuccessivelyin predetermined proportion to the rate oi.' angularmovement oi' a givenobject, thus giving a measure of the angularmovement of such object in a given period of time.

The invention is illustrated as directly applied to a gun 5 mounted bymeans of trunnions 6 in a top carriage 7 which is rotatably supported 60on a base 8.

Referring to Fig. 3, the' re control apparatus consists essentiallyofsimilar rate mechanisms, one designated at A being horizontallypositioned for association through actuating mechanism B with the topcarriage 'l and the ,other designated at C being vertically positionedfor association through actuating mechanism D (see Fig. 1) with the guntrunnions 6. Accordingly, the mechanism A deals with the relativeangular travel or position of the target in azimuth and the mechanism Cfunctions in a similar capacity with regard to elevation. The termelevation as used herein refers to both plus and minus elevation, thatis, .elevation above the horizontal and depression below the horizontal.

The rate mechanisms A and C are disposed out of line in a housing E sothat they may be more conveniently driven by, a constant speed motor Fof any suitable character. As seen in Figs. land 3, the driving shaft 9from the motor F meshes with a pair of gears 10 and 11, the former faston the shaft of the vertical mechanism C and the latter connected to theaxis of the horizontal mechanism A through the shaft 12 and gear- 85 ing13. f

As the rate mechanisms aresubstantially alike, only one will bedescribed in detail. Referring especially to Figs'. 4 and 5 the drivenaxis 14 of the mechanism is in the form of a shaft on 80 which issecured a drum or cylinder 15, in-the 'present instance these membersbeing formed integrally. A plurality of similar slide racks 18conveniently arranged about the periphery of the drum are mounted forlongitudinal movement 95 parallel to the axis by means of tongues 17(see Fig.\ 5) on opposite ends of eachrack tting ih grooves 18 in thevThe grooves are se rated centrally of the drum by a diaphragm 18 whichforms a seat for a pair of springs 20-20 l0 conijined by the tongues1'1.

For the purpose of adjusting the springs 20 to properly position theslides 16 there may be provided adjusting screws 17a threaded in tongues17 which are drilled and tapped for this purpose. 1(

The actuating mechanism B consists of a shaft, in this instance having aflexible portion, geared through the usual traversing pinion (not shown)with e ring gear (not shown) on the base 8 $9 that movement of a topcarriage when travers- 1I ing the gun will cause rotation of the shaft.The actuating mechanism D in this instance consists of a train of gearsactuated through movement of the gun in elevation.

Slidably mounted in the shaft 14 is a rod 21 to which the longitudinaldisplacement of the individual racks 16 -is constantly communicated.Inasmuch as this displacement may be in opposite directions, theconnection with the rod 21 is established through aA bridge 22, one endof which embraces and is secured to the rod and the other end isslidably mounted on the axis 14. The ends of the bridge confine springs23-23 whose inner ends are seated on pressure plates 24-24, one at eachend of the drum and extending over all of the racks.

The actuating mechanism B or D includes a pinion 25, mounted in positionto mesh with the racks. The rate at which this pinion is rotated iscontrolled by the movement of the gun, telescope or other instrument infollowing the target, vertically or laterally, and affords a measure ofthe relative rate of angular travel of the target.

In order that a rack 16 when displaced by the pinion 25 may be held indisplaced position when disengaged from the pinion while the pinion isacting on the succeeding rack, there is provided a pawl 26 (see Figs. 5and 6) carried in a fixed member such as the housing E and positioned ata predetermined' distance from the pinion, preferably slightly lessvthan the width of one rack 16 and in position to mesh with the racks 16on the revolving drum. The pawl 26 may be rigidly mounted but ispreferably held in a balanced or neutral position by opposite springs 27which have sufficiently greater strength than the springs 20 to insureretention of the rack 16 in the displaced position so long as the pawlis in engagement therewith. f

The pawls 26 in this instancehave' teeth which mesh with the teeth ofthe slides 16 so that a slide 16 is held by the pawl in the positionwhich it has when brought into contact with the pawl until the slide isagain moved out of engagement with such pawl.

In direct re the lead angle, which must be given the gun to compensatefor the speed factor is applied by deviating the line of sight withrespect to the axes of direction of the gun. Within limited ranges wherethe error resulting from reduction in muzzle velocity is negligible andpermissible because of the dispersion of the cone of the trajectory ofthe bullets, the measure of angular rate as determined during theobserving interval may be utilized to directly establish the amount oflead to be applied to the gun. For a known muzzle velocity and sightbase the movement imparted to the rod 21 to correctly represent the leadfor a. definite "rate is determined by proportioning the width of theracks 16 and the speed of themctor F.

In accordance with the foregoing a rod 28 on which is a rear sight 29 isassociated with the vertically movable rod 21 of the rate mechanism C,being y:mounted in a guide 30 thereon so as to be/,capable of horizontalmovement through an arm 31`f`secured to the bridge 22-of the ratemechanism A. The lateral and vertical displacement of the rear sightproduced by the rate mech-lv Similar to the favorable application of thedevice for firing at limited ranges will be its adaptation for bombingat low altitudes where the'acceleration of the bomb may be neglectedbecause of the member dropped or the size of the target.

When the problem of determining the vertical lead corresponding togreater ranges or altitudes is undertaken, consideration must be givento the trajectory of the projectile and the effect thereon of the angleof departure. In conformity with standard practice 'a grid sight 32 (seeFig. 8) may be employed in lieu of the sight 29. In this sight thehorizontal wires are calculated to give proper tangent corrections forhorizontal i'lre at the ranges marked on the sight. This sight when usedas a front sight is customarily suspended as a pendulum to automaticallyreduce the maximum horizontal correction by the proper amount as theangle of departure increases until ihe correction reaches zero when theangle of departure is 90 or perpendicular. 'Ihe movability of thefrontsight is inherently unsatisfactory because of its tendency to oscillateand it is, therefore, possible to introduce the angle of elevationcorrection into the movement of the rear sight by including in theactuating mechanism D a pair of driving members 33 and 34 whichv arecalculated to vary the movement of the pinion 25 an'd the rear sight 29,in accordance with the change in the angle of elevation.

f The effect of range on the lateral deflection may be introduced intothe actuating mechanism B by inserting therein a differential gearing 35which will result in obtaining the product of the rate by the time ofight corresponding to range.

The sight may also be in the form of a bar 36 (see Fig. 7) whose stem 37may be carried by the rod 21 of the vertical rate mechanism C androtated through connection with the bridge 22 of the horizontal ratemechanism A.

In the angular travel method of fire control,

as applied to bomb sights and anti-aircraft directing apparatus, thevertical and lateral corrections are determined by measuring the angulartravels during a unit of time and multiplying this factor by the time offlight. Electrical devices for interpreting the rproblem are unsuitedfor field service because of their delicate construction and becausethey are influenced by climatic conditions. Mechanical devicesinvariablyemployed are variable speed mechanisms of the disk and roller'type having interposed balls. The friction drive-communicated by theballs gives rise to considerable lost motion and the data obtainedcannot, therefore, be accurate. Distinguished from the foregoing therate mechanism of the present invention being provided with a positivedrive will aftord precise measurements orindications of the angular rateof travel for application in an integrating device.

The operation of the device is as follows: the motor F is running' at apredetermined rate of speed/thereby rotating the rate mechanisms ordrums A and C at la known rate. While the gun or other movable object 5remains stationary the slides 16fretain their normal position and theline of Sight remains in parallelism with the longitudinal axis of thegun or other movable object 5. If, however, the object 5 is moved inelevation the gear 34, by reason of its meshing with the stationary gear33, will rotate causing rotation of the train of gears D and through thepinion 25 moving a slide 16. vThis movement of the' slide \16`will be ameasure of the angular @movement of the object 5 during the time thataecomo f; inemesh with the pinion 25. Movement of a slide 16 causesmovement of the bridge 22 through movement of a plate 2t and consequentunbalancing ot the springs 23-23. This movement of the bridge 22 isimparted through shaft or rod 21 to the bue 30 in which the `sight stem28 is carried, thus moving the sight 29 and throwing the line of sightout of parallelism with the longitudinal axis of the object 5. As theslide 15 p from contact, by reason of the revolution of the drum C. withthe pinion 25, it comes into contact with a pawl 26 by which' it is heldin its altered position until the next slide is passing from contactwith the pinion 25.

From the foregoing it will be clear that the device operates to give ameasure oi the angular movement of an object in a given period of timeand that by properly proportioning the gearing through which the slides16 are moved this movement, in directing gun re, may be made toautomatically set in the lead angle made necessary by reason of speed oithe target. It is also evident that by developing the gears 33? and 3dfrom the curves of relation between superelevation and quadrantelevation the slides may be made to move so as 'to properly set thesights to automatically correct for superelevation.

anismAisthesameasthatoutlinediorthe mechanism C except that in this casethe pinion 25 is driven through shaft B which is rotated through theusual traversing pinion (not shown) fast on the lower end of such shaftand with the ring gear (not shown) on the base 8. This gearing is soproportionedas to give a move= ment to the slides proportional tolateral deection. When desired to take account of the eect of range onlateral deection a dierentlal 35 may be inserted in the shaft B Iandoperated in wir' well-known manner to secure a movement ci the pinion 25which will be a measure of the product oi the rate by the time of iiightcorrespondlng .to range.

I claimt' In combination with a member mounted for `movementl intraverse and elevation, a vertical rate mechanism operable upon movementin elevation of the member, a horizontal rate mechanism operable upontraverse of the member, each of said rate mechanisms including a drumseries of gear-driven slides mounted on said drum to `slide axiallythereof in either direction from a f normal position, a memberdisplaceable by said slides, a sight mounted on the displaceable memberof the vertical mechanism, and means connecting said horizontalmechanism with the sight e for denecting the latter in a horizontalpiane. In traversing the gun the action of the mech- RICHARD C.COUPLAND.

